Lately, I have found about a new study that took place in Wake Forest University School of Medicine, NC, USA. The new study is titled “Mindfulness meditation improves cognition: evidence of brief mental training” and you can read its abstract on the U.S. National Library of Medicine
National Institutes of Health.

The authors tried to see if the unexperienced meditators had any benefits from meditation after only several days of simple meditation. They also had a control group that listened to an audio book, instead of meditating. The results were that meditation was more beneficiary in many aspects. From the abstract:

We examined whether brief meditation training affects cognition and mood when compared to an active control group. After four sessions of either meditation training or listening to a recorded book, participants with no prior meditation experience were assessed with measures of mood, verbal fluency, visual coding, and working memory. Both interventions were effective at improving mood but only brief meditation training reduced fatigue, anxiety, and increased mindfulness. Moreover, brief mindfulness training significantly improved visuo-spatial processing, working memory, and executive functioning.

The group only had 4 days of meditation (20 minutes each day) and the benefits were already apparent. The authors of the article also suggest that in more experienced meditators the beneficial effect should be more profound.